Re: [PATCH] ARM: Allow pre-ARMv5 builds with ld.lld 16.0.0 and newer

From: Nathan Chancellor
Date: Sun Jan 29 2023 - 09:53:47 EST


On Fri, Jan 27, 2023 at 10:56:06PM +0100, Arnd Bergmann wrote:
> On Wed, Jan 18, 2023, at 20:22, Nathan Chancellor wrote:
> > Commit 6a7ee50f8f56 ("ARM: disallow pre-ARMv5 builds with ld.lld")
> > prevented v4 or v4t kernels when ld.lld will link the kernel due to
> > inserting unsupported blx instructions.
> >
> > ld.lld has been fixed in current main (16.0.0) to avoid inserting these
> > instructions by inserting position independent thunks instead. Allow
> > these configurations to be enabled when ld.lld 16.0.0 is used to link
> > the kernel.
> >
> > Additionally, add a link to the upstream LLVM issue so that the reason
> > for this dependency is clearly documented.
> >
> > Link: https://github.com/ClangBuiltLinux/linux/issues/964
> > Link:
> > https://github.com/llvm/llvm-project/commit/6f9ff1beee9d12aca0c9caa9ae0051dc6d0a718c
> > Suggested-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
> > Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx>
>
> Thanks a lot for getting this fixed!
>
> I gave this a spin on my randconfig build setup, which showed
> nothing unusual.
>
> Tested-by: Arnd Bergmann <arnd@xxxxxxxx>
>
> Please add this to Russell's patch tracker.

Done, thanks for testing!

https://www.armlinux.org.uk/developer/patches/viewpatch.php?id=9289/1

Cheers,
Nathan